After colorectal and anorectal interventions for chronic inflammatory bowel diseases, specific complications can occur.In Crohn's disease these complications mainly occur after proctocolectomy. Pelvic sepsis can be prevented by omentoplasty with fixation inside the pelvis. A persisting sepsis of the sacral cavity can be treated primarily by dissection of the anal sphincter which ensures better drainage. In cases of chronic sacral sepsis, transposition of the gracilis muscle is a further effective option. Early recurrence of a transsphincteric anal fistula should be treated by reinsertion of a silicon seton drainage.Complications after restorative proctocolectomy are frequent and manifold (35%). The main acute complications are anastomotic leakage and pelvic sepsis. Therapy consists of transperineal drainage of the abscess with simultaneous transanal drainage. Late complications due to technical and septic reasons are still a relevant problem even 36 years after introduction of this operative technique. A consistent approach with detailed diagnostic and surgical therapy results in a 75% rescue rate of ileoanal pouches.